Hoisting device

ABSTRACT

A hoisting device of the type in which a rope is wound around a drum to provide a plurality of windings in side by side substantially parallel relationship. The shunting of the rope from one winding to the adjacent winding and the tensioning of the rope is accomplished by rollers so as to provide automatic self-reeving action and to reduce power loss due to friction as well as minimizing rope wear and enhancing reliability of the hoisting apparatus.

United States Patent Arnold [541 HOISTING DEVICE [72] Inventor: Carter11. Arnold, 317 Rocky Point Road, Palos Verdes Estates, Calif. 90274[22] Filed: Sept. 4, 1970 [21] Appl. No.: 69,709

[52] U.S. Cl. ..254/150, 254/190, 242/117, 242/4701, 254/D1G. 11 [51]Int. Cl. ..B66d 1/30 [58] Field of Search.254/150, 190, DIG.1l;242/117,242/4701, 54; 187/23 [56] References Cited UNITED STATES PATENTS 772,07410/1904 Wellman ..187/23 2,917,279 12/1959 Arnold ..254/150 2,976,0173/1961 Le Bus ..254/l90 2,922,623 1/1960 Simmons ..254/19 0 X 3,226,09012/1965 Sauerbrey ..254/190 3,353,793 11/1967 Nelson .1..254/190 [1513,707,275 [451 Dec. 26, 1.972

FOREIGN PATENTS OR APPLICATIONS 112,967 111945 Sweden ..254/D1G. 11L13,325 1/1956 Germany .....254/190 956,441 12/1956 Germany 656,661Great Britain ..242/117 7 Primary Examiner-Harvey C. l-lornsby AssistantExaminer-Merle F. Maffei Attorney-Gordon Wood 51 ABSTRACT 12 Claims, 13Drawing Figures PATENTEDBEM J R 3.707 275 sum 1 [1F 5 v ATTORNEYPATENTED DEC 2 6 I972 SHEET 2 [IF 5 .FIE- ,5

ATTOKA/fy PATENTED DEC 2 6 i972 SHEET 3 [1F 5 BY CANE/8 DT WM M arr-071ATTORNEY PATENTEI'] DEC 26 m2 1 3 707' 2 75 sum u or 5 INVENTOR.

CARTER H. AKA/0Z0 Y Mar?! ATTOKNEV PATENTED DEC 2 6 1972 SHEET S 0F 5FIE:-

INVENTOR (METER ARA/01D BY FICT 1Z HOIS'IING DEVICE This inventionrelates to an improved hoist of the type in which a rope is wound arounda drum to provide a plurality of windings in side by side relationship.The invention provides certain improved features over the hoist diclosedin US. Pat. No. 3,063,653.

Prior art hoists of the subject type usually include a drum having aplurality of peripherally extending parallel grooves in which the ropewindings are received and the shunting of' the rope from'one winding toan adjacent winding is accomplished by guide elements fixedly securedrelative to the housing of the drum. Since the forces on the rope arenormally quite high the engagement of the rope with the shuntingelements has created a considerableamount of friction with its attendantloss of power'and has also caused wear on the rope and the shuntingelements. 'By the present invention both wear and friction are minimizedby providing rollers for shunting the rope from one winding to anadjacent winding. Furthermore, by the present invention the tensionrollers which apply tension to the rope are driven in the direction oftravel of the rope so as to further minimize wear and friction.

Another limitation of hoists of the type shown in US. Pat. No. 3,063,653is that they are designed for use in hoisting applications wherein oneend of the rope is always loaded and the other end is always slack. Thehoist of the present invention lends itself to use in'hoistingapplications wherein either end may be loaded or unloaded.

Another advantage of the present-invention is that a closed tamper proofhousing is provided and the drum is made self-reeving by a uniquearrangement of the tension and transfer rollers. With this self-reevingfeature the proper operation of the rollers can not be in- .terferedwith even by the operator and, when the drum is first reeved, it may bedone simply by feeding the rope in an opening in the housing so thatsaid rope is reeved around the drum and shunted from one groove toanother automatically without intervention of the operator.

Other objects and advantages of the invention will be apparent from thefollowing specification and from the drawings: I I I FIG. 1 is a sideelevation of the hoist with one side broken away to show internalstructure;

'FIG. 2 is a schematic perspective of the rope windings showing themanner in which the transfer rollers act on the rope;

FIG. 3 is a partial elevation and vertical section through the hoisttaken in a plane indicated by lines 3 3 of FIG. 1; v

FIG. 4 is a schematic developed view of the rollers around the peripheryof the drum showing their contours and arrangement relative to eachother;

FIG. 5 is a view similar to FIG. 4 showing the shunting action of thetransfer rollers;

FIG. 6A is a schematic view of a portion of the drum periphery showingthe manner in which the drum drives the rollers FIG. 6B is a viewsimilar to FIG. 6A but with the drum rotating in the opposite direction;

FIG. 7 is a longitudinal section through a tension roller and theperiphery of the drum as taken in a plane indicated by lines 7 --7 ofFIG. 1;

FIG. 8 is a longitudinal section through a transfer roller and theperiphery of the'drum as talten in a plane indicated by lines 8--8 ofFIG. 1; and

FIG. 9 is a schematic of a hoisting arrangement wherein both ends of therope may be loaded;

FIG. 10 is a vertical sectional view partly in elevation of a modifiedrope guide for testing the straightness of the wire;

FIG. 11 is a fragmentary expanded top plan view of the drum peripheryadjacent the-rope windings showing a modified form of the invention;

. FIG. 12 is a fragmentary cross section through the drum as taken in aplane indicated by lines 12-12 of FIG. 11. I

In detail, and first with reference to FIG. 3, the invention includes ahousing generally designated. 1 which supports an electric motor or airmotor 2 which in turn drives a worm gear 3 through a worm 4. The wormgear 3 drives a drum shaft 5 which in turn is rotatably supported onside plates 6,7 of housing .1. Control of the hoist may be'effected byswitches (not shown) actuated by handle 8. Fixedly secured to shaft 5 isthe hoisting drum 10. In the particular application shown in FIGS. 1,3 ascaffold or other load may be con nected to housing 1 by support member9.

The periphery of drum 10 is provided with a plurality ofcircumferentially extending parallel grooves which are numbered 11 to 16from right to left in FIGS. 7 and 8. As will be seen later on thetension end 18 of rope 20 is received in the first groove 11 and extendssubstantially 300 around said groove until it is shunted to groove 12.The rope is wrapped in groove 12 for substantially 300 until it isshunted to groove 12 and so on until the rope is fed off groove'l6 toconstitute the tail end or slack end 19 of the rope.

The shunting from groove. 11 to groove 12 is performed by a transferroller 21 (see FIGS. 1, 4 and 5). Similarly the transfer from groove 12to groove 13 is performed by a transfer roller 22. In like mannertransfer rollers 23, 24, 25 shunt the remaining windings into theadjacent grooves until the tail end 19 of the rope is discharged fromthe drum and out of engagement with the last groove 16.

The action of the above noted transfer rollers has been described withreference to rotation of the drum 10 in a counterclockwise direction asseen in FIGS. 1 and 2 so that the load carried by the housing 1 israised along the length of the tension end 18 of the rope. An additionaltransfer .roller 26 is provided which is inoperative when the hoist isgoing up, but becomes operative when the hoist is being lowered. In thislatter case transfer roller 26 functions to shunt the rope from groove16 into groove 15 and rollers 25, 24, 23 and 22 actto shunt the ropefrom groove to groove until the last groove 11 is reached and the ropeis discharged as tension end 18. When the hoist is thus operated tolower the load transfer roller 21 becomes inoperative.

Transfer roller 22 and the mounting thereof is shown in detail in FIG. 8and the roller comprises a generally cylindrical body portion 30 whichis provided at its opposite ends with sleeve bearings 31 for rotatablysupporting the roller structure on a fixed shaft 32 extending betweenopposite side plates 6,7 of the hoist houswell into the associatedgroove 12 of the drum thereby permitting a smooth shunting action of therope.

Surrounding the body portion 30 of the roller 22 is a shell'37preferably formed of a tough resilient plastic material such aspolyurethane. As will be seen later on this shell .37 is contoured toprovide annular grooves cooperating with the rope in a manner to bedescribed. The opposite ends of the roller 22 are diametrically enlargedand formed to provide a pair of generally axially directed frustoconicalsurfaces 38,39 which are adapted to cooperate respectively withcomplementary formed enlarged ends 40,41 ofdrum 10;

The body portion 30 of roller 22 is preferably formed of steel and theopposite ends 38,39, engaging the ends 40,41 of steel drum 10, act toposition the transfer roller in a predetermined position axiallyrelative to the drum thereby properly positioning the wire windings. A

slight axialshifting of roller 22 is permitted to conform to theinherent t'endencyof the rope windings to walk axially along the lengthof the drum due to the helical form of the windings; Depending upon theI direction of rotation of the drum the roller 22 is urged against oneor the other of the ends 40,41 of the drum providing a substantiallypositive positioning of the windings. By this structure it will beapparent that no thrust from the windings is transferred to the sideplates 6,7 of the housing but is absorbed by the drum l0.

The remaining transfer rollers are identical in structure and mountingto the above described roller 22 except that, as seen in FIGS. 4, and 6,the annular projection 35 is in a different position for each roller asindicated since said projections cooperate with different grooves of thedrum 10.

Atspaced points around the periphery of the drum l0 and interposedbetween each pair of adjacent transfer rollers are a plurality oftension rollers which are spring urged radially inwardly of the drum inorder to enhance the frictional engagementbetween the rope and theperiphery of the drum. In additionto the tension rollers interposedbetween pairs of transfer rollers and numbered 43 to 47, additionalsimilar tension rollers 48,49,50'are also provided, it being understoodthat the greater number of tension rollers the greater will be thetraction developed between the rope and the drum periphery. The requiredpressure in the rope is thus reduced and reeving made easier.

In FIG. 7 tension roller 43 is shown in detail and it is seen that thesame is provided with an inner cylindrical portion 53 to the oppositeends of which are secured sleeve bearings/S4 rotatably supported onshaft 56. The opposite ends of shaft 56 are mounted in blocks 57,58slidably supported for movementradially of the drum in grooves 59,60formed in side plates 6,7 of the housing 1. The blocks 57,58 are urgedradially inwardly of the drum 10 at all times by means of compressionsprings 62.

Mounted on the sleeve 53 of roller 43 is a shell 64 also preferablyformed of polyurethane plastic and peripherally formed to cooperate withthe rope windings in a manner to be described. The remaining tensionrollers are similar to roller 43 in construction and mounting" exceptthat their peripheries are appropriately formed depending upon thelocation of the tension rollers relative to'the rope windings. As in thecase of the transfer rollers the tension rollers are similarly formedwith frustoconical ends 66,67 adapted to cooperate with thecomplementarily formed end portions 40,41 of the drum 10. As can beseenin FIG. 7 the steel drum 10 is driving the polyurethane tension roller43 by frictional engagement with the left hand end of the latter. Aswill beseen later on, upon reversal of the direction of rotation of thedrum tension roller 43 is shifted to the right in FIG. 7 so that theroller is driven through engagement of the drum with its right hand end.

in FIGS. 2, 5 and 6B the engagement between rope and the transferrollers is shown for the condition in which the drum 10 is rotating-in acounterclockwise direction as seenin FIG. 1 and the rope is moving rela:tive to the housing in a direction from right to left in FIGS. 5 and 6B-When the direction of rotation is reversed andthe rope is drivenrelative to the housing from left to right as seen in FIG. 6A theopposite sides of transfer rollers 22, 23, 24 and 25 become active andtransfer roller 26 functions to shunt the rope from groove 16 to groove15 but in such an event transfer roller 21 becomes inoperative. Thisaction can best be seen with reference to FIG. 5. l

. Also with reference to FIGS. 5, 6A and'6B it is seen that the shuntedportions of the rope'between adjacent transfer rollers change theirpositions depending upon the directionof rotation of the drum 10. Thischange of position of the juncture between adjacent windings and theactual shifting of the rope windings within their grooves is employed toshift the tension rollers axially of their supporting shafts so that therollers are driven by different sides of the drum 10. In this manner thedirection of movement of the rope engaging portions of the rollersrelative to the adjacent rope windings is the same as the direction ofmovement of the drum periphery. For this reason power loss by frictionbetween the rope and the rollers is considerably reduced. Furthermorefrom a consideration of FIG. 7 it will be seen that the linear speed ofthe rollers at their points of engagement with the rope is slightlygreater than the speed of the rope itself so that the rollers actuallytend to urge the rope forward in whatever direction the latter istraveling. This urging of the rope forwardly is resilient in naturesince the drive between the drum and the rollers relies on friction.Excessive wear on the rollers by the rope is therefore avoided.

Because of the fact that the windings and the junctures between adjacentwindings of the rope 20 shift depending upon the direction of rotationof the drum the peripheral grooves in the tension rollers areappropriately formed to permit continuous frictional engagement with therope. For example in FIG. 7 the relatively wide groove 69 that receivesthe rope 20 is of sufficient width to permit the shifting of theassociated rope juncture depending upon the rotation of the latter. Theminimum diameter of groove 69 is also less than the minimum diameter ofthe remaining grooves since the rope 20 is displaced radially outwardlybetween adjacent grooves. This same method of forming the the shell 37in FIG. 8.

One of the most important features of the present invention is thearrangement of transfer rollers and tension rollers as above describedwhich results in the guided by the tension rollers and transfer rollersuntil it reaches transfer roller 21 which shunts it into adjacent groove12 where it is immediately gripped by tension.

roller 50 and passed through short guide 72 into the control of tensionroller 49 and so on. After all of the windings have been formed the ropeis then discharged out the tail end through a guide 73. It will beapparent that this self-reeving feature is realized whether the' rope isfed into the upper end or into the lower end of the housing. Since it isnever necessary for the operator to open the housing it is impossiblefor him to make any mistake of judgment that would adversely affect'theoperation of the hoist and effective traction between the rope and thedrum is established at all times making undue slipping impossible.

In the particular application of the hoist shown in FIGS. 1,3 whereinrope end 18 is always the loaded end and tail end 19 is always slack thewear between the rope and drum may be reduced and the traction enhancedby forming the grooves receiving the windings having the greatesttension to a larger diameter than the remaining windings. For example ina drum having a nominal diameter of 8 inches groove 11 may be, forexample, 0.0l4 inch greater in diameter than groove 12 and the latter is0.006 inch greater in diameter than groove 13. Since the last threegrooves 14-16 are under comparatively little tension they may be ofequal diameter. This graduation in groove diameter-appropriately adjustsfor the fact that the stretch in the rope adjacent the loaded end 18 isgreater than adjacent the slack end. Thus wear is reduced and tractionimproved because the length of each winding, having regard for thetension therein, closely conforms to the peripheral extent of itsrespective groove. It will be apparent that the above describedgraduation of groove diameters is not appropriate if either end of therope may become loaded.

The performance of the hoist of FIGS. 1,3 may be enhanced by forming thefrustoconical end portion 66 to a slightly smaller effective diameterthan the opposite end 67. Referring to FIG. 7 it is seen that, as thehoist is raising the load, the tension roller 43 is being driven by theleft hand end 40 of the drum and the tail end of the rope is urged outof groove 16 by roller 43 which, acting at a greater radius on drum hasa greater peripheral speed than the drum. On the other hand when thedrum rotation is reversed frustoconical end 67 acting at a smallerradius on shoulder 41 provides a slight drag with respect to theunloaded end. The result of this structure is that the windings are moreeffectively urged against the grooves and traction is improved. I

The hoisting arrangement of FIGS. 1,3 is appropriate for use in raisingand lowering scaffolding, however the invention is not restricted tosuch an arrangement. For example in FIG. 9 there is shown schematicallya hoisting arrangement wherein the hoist housing 1' is fixed to anelevated structure and the rope ends 18, 19' are run over sheaves 80,81and are connected to cages 82,83 respectively. In this arrangement thecages 82,83 may be simultaneously loaded and unloaded or one load may beemployed as a counterweight to permit raising the other with twice theload for a given horsepower than if no counterweight were present.

The present invention lends itself to this last mentioned applicationbecause of the fact that the tension rollers and shunt rollers areprovided at spaced points around the entire periphery of the drum sothat adequate traction is provided at all times regardless of thedirection of drum rotation and regardless of the" tension differentialin the rope ends. As stated above a drum having graduated groovediameters is not used in an arrangementsuch as shown in FIG. 9.

Not only does the use of transfer rollers as distinguished from fixedguides reduce the wear and loss of power but it also prevents excessivewear and damage to the rope.

' It has been found that better traction is achieved between the ropeand drum of hoists of this character when a maximum number of relativelylight radially inthe recesses so that a portion of the inner side of therope is in engagement with said plastic. (See FIGS. 7,8).

The provision of the plastic 78 results in a reduction of the effectivearea of engagement between the rope and the hard metal of the groovethus increasing the unit pressure. The plastic 78 also keeps foreignmatter out of the bottom of the groove and improves the reeving action.

It will be understood that in order to achieve the above describedself-reeving feature it is desirable that the end of the rope which isinserted into the hoist be as straight as possible so as to minimize anytendency of the rope to be deflected out of the control of the transferrollers and tension rollers. This problem is of course aggravated if theperipheral spacing between the rolls is increased.

In FIG. 1 a tubular guide is shown to direct the end of rope 18 to shortguide 72 and tension roller 49. An alternative arrangement isillustrated in FIG. 10 wherein the rope. 18 is inserted into the housing1 through a tubular guide 86 formed with an enlarged diameter section87. This section 87 connects at its lower end with a flared portion 88which in turn connects with a continuation 89 of guide 86.

The lower end of enlarged section 87 thus provides an annular shoulder90 which engages and acts as an abutment stop for the end of the wire inthe event the terminal portion of the wire deviates from a straight linebeyond a predetermined limit. For example, the terminal portionschematically indicated by dot dash proper selforeeving past the.various rollers unlikely.

The operator cannot insert said terminal portion 18 through the enlargedSection and is obliged to withdraw the wire and straighten the same to asufficient degree of straightness that the end of the wire passes theshoulder 90. in FIG. 10 a slightly bent wire indicated by dotted linesat 18" straightness to pass the annular shoulder 90 and therefore passthe various rollers to insure the self-reeving feature.

-It will be apparent that the length of enlarged section 87 and theinside diameter'of. annular shoulder 90 may be varied to test thestraightness of the wire so that any predetermined degree ofstraightness may be achieved. 4

ln FlGS. 11, 12 there is illustrated a modified form of the inventionwhichmay be employed to enhance the self-reeving action in the,event'the wire rope. is not straight or the rope is frayed or otherwisedamaged and includes loose strands of wire. ln this connection it willbe understood that the use of a damaged wire rope increasesthelikelihood that one or more loose strands may enter the'smallspace-between the outer periphery of one of the transfer rollers and itsassociated groove on the drum. If this in fact occurs the coactionbetween the transfer roller and the drum could pull the remainder of therope into said small space thus causing additional damage to the wirerope. Naturally it is not good practice to employ wire rope that is notin good condition but in the interest of safety it is desirable to takeall possible precautions against'improper usage.

ln FIGS. 11, 12 that portion of the drum 10 that cooperates withtransfer rollers 23, 24, is shown together with tension rollers 45;46JThis embodiment of the invention includes a fixed guide 92 positionedon each side of each transfer roller. Each guide is carried by a shaft93 which is fixedly secured at its opposite ends in side plates 6, 7. itwill be seen in FIG. 11 that guides 92 may be made from relatively thinplate and are secured to their supporting shafts 93 at an angle so thatthey are coplanar with the central plane of the associated transferroller.

Further with reference to FIG. 11 it is seen that the guides 92associated with transferroller 24 serve to constrain the rope betweenthe adjacent tension roller and the transfer roller. For example, while.the rope is being reeved on the drum and traveling from right to left asseen in FIG. 11 the rope end coming from the tension roller 46 strikesthe guide 92 between said tension roller 46 and transfer roller 24 andis directed to the working side of the latter. In this manner theshunting of the rope into the influence of tension roller 45 is mademore smoothly. More importantly, if the rope is frayed and includesloose strands there is very little liklihood that such loose strandswill enter the small approaches from the left, then the fixed guide 92on the left side of roller 24 deflects the rope to the working side ofroller 24. This action of the rope is indicated by dotted linesin FlG.1 1. Thus by providing a fixed guide has a sufficient degree of 7 oneach side of each transfer roller the hoist is guarded against failureby the use of damaged wire regardless of the direction of rotation ofthe drum.

The inner edge of each guide 92 may be positioned closely adjacent theperiphery of the drum and, as shown in FIG. 12, the extent of each guidemay be increased toward 'the drum to provide substantially completerestraint of the wire at all times.

It will be understood that some variation in the particular location ofthe shunting rollers may be made over that shown in FIG. 1. It will beunderstood that it is preferable to permit the first winding-fromtension end 18 to substantially encircle the drum before said firstwinding is shunted from groove. 11' to groove 12 (F l6. 7). In thismanner traction is improved since an optimum length of contact betweenthe tensioned end of the rope and the drum results. Similarly the secondwinding should be as long as possible before it is shunted .into thethird groove and so one. For this reason shunt roller 21 could be movedcloser to the tensioned end 18 of theropeand, in fact, could beinterchanged with tension roller 50. ln a similar manner.

shunt roller 26 could be interchanged with tension roller 48. The,arrangement thus resulting would be similar to that shown in pendingapplication Ser. No. 69,710 filed Sept. 4, 1970. a

l-lowever it will be apparent that the first winding, as disclosedherein,fand subsequent windings engage the drum along substantially theentire periphery of the latter before being shunted to the next groove.

I claim:

l. A hoisting device comprising:

ahousing, I

a drum rotatably mounted in said housing, said drum being formed with aplurality of axially spaced parallel grooves in planes perpendicular tothe axis of said drum, I

a rope formed intermediate its ends to provide a plurality of windingsrespectively received in said grooves and junctures connecting adjacentwindings,

means for deflecting said rope from one winding to an adjacent windingduring rotation of said drum with the deflected portions of said ropeforming said junctures in engagement with the periphery of said drum, I

said deflecting means comprising a roller free for axial movement androtatably supported in said housing and in engagement with a winding ofsaid rope at one side of the latter,

said drum being formed at one of its opposite ends with an annularcoaxial abutment and said roller being formed with an annular abutmentadapted to engage said drum at said drum abutment to limit movement ofsaid roller axially relative to said drum.

2. A device according to claim 1 wherein said drum is formed with acoaxial abutment at each end and said roller is rotatably supported on ashaft carried by said housing and is adapted to shift axially on saidshaft into engagement with one or the other of the abutments on saiddrum.

3. A device according to claim 1 wherein said roller is provided with aperipherally extending groove in registration with an adjacentundefiected winding therein.

4. A hoisting device comprising:

a housing,

a drum rotatably mounted in said housing,

said drum being formed with a plurality of axially spaced parallelgrooves in planes perpendicular to the axis of said drum,

a rope formed intermediate its ends to provide a plurality of windingsrespectively received in said grooves and junctures connecting adjacentwindings,

means for deflecting said rope from one winding to an adjacent windingduring rotation of said drum with the deflected portions of said ropeforming said junctures in engagement with the periphery of said drum,

a tension roller free for axial movement and supported for rotationrelative to said housing,

means urging said roller radially inwardly of said drum, i

said roller being provided with a plurality of peripherally extendinggrooves adapted to receive said rope windings therein for reducing thepressure on said rope,

said drum being formed at one of its opposite ends with an annularcoaxial abutment and said tension roller being formed with an annularabutment adapted to engage said drum abutment to limit movement of saidroller axially relative to said drum. I

5. A device according to claim 4 wherein said tension roller issupported for axial movement to permit shifting of said roller by saidrope windings. i

6. A device according to claim 4 wherein said drum is formed at each ofits opposite ends with an axially inwardly directed coaxial shoulder andsaid roller is supported for slidable axial movement into engagementwith one or the other of said shoulders.

7. A hoisting device incorporating automatic reeving wherein a wire ropeis reeved around a drum in a plurality of windings and means is providedfor leading the free end of such rope circumferentially around said drumto so form said windings without manual intervention, said devicecomprising:

a housing,

a drum rotatably mounted on said housing,

a rope formed intermediate its ends to provide a plurality of parallelwindings in planes at right angles to the axis of said drum,

means for holding said windings against axial shifting relative to saiddrum, I

shunt rollers for deflecting said rope from one winding to an adjacentwinding during rotation of said drum with the deflected portions of saidrope in engagement with the periphery of said drum,

a plurality of tension rollers arranged in a circular row around theentire periphery of said drum, and

means for urging said tension rollers radially inwardly of said drum andagainst said windings to increase the traction ofthe latter relative tosaid drum,

adjacent of said shunt and tension rollers being spaced sufficientlyclose together that the end of a semi-rigid rope being reeved around thedrum and extending tangentially from said drum under one roller isdeflected radially inwardly toward the drum by an adjacent roller toallow such automatic reeving. 8. A device according to cla1m'7 wherein ashunt roller is interposed between at least one pair of adjacent tensionrollers.

9. A hoisting device comprising:

a housing,

a drum rotatably mounted in said housing,

said drum being formed with a plurality of axially spaced parallelgrooves in planes perpendicular to the axis of said drum,

a rope forward intermediate its ends to provide a plurality of windingsrespectively received in said grooves and junctures connected adjacentwindings,

means for deflecting said rope from one winding to an adjacentwindingduring rotation of said drum with the deflected portions of saidrope forming said junctures in engagement with the periphery of saiddrum,

said rope having 'a loaded end and a slack end whereby the tension insaid rope decreases along the lengths of said windings toward said slackend,

said groove being formed to a larger diameter at said loaded end than atsaid slack end to reduce the relative movement between rope and drum andto improve traction and decrease wear,

the difference in diameter between the loaded and slack ends of the drumbeing in the orderof the difference in lengths of the windings at saidends due to elongation of the rope at said loaded end.

10. A hoisting device comprising:

a housing,

a drum rotatably mounted in said housing,

said drum being formed with a plurality of axially spaced parallelgrooves in planes perpendicular to the axis of said drum,

a rope formed intermediate its ends to provide a plurality of windingsrespectively received in said grooves and junctures connecting adjacentwindings,

shunt rollers for deflecting said rope from one winding to an adjacentwinding during rotation of said drum with the deflected portions of saidrope forming said junctures in engagement with the periphery of saiddrum,

each of said rollers being rotatably supported in said housing and eachbeing positioned with its axis of rotation substantially parallel to theperiphery of said drum and spaced apart peripherally of said drum froman adjacent roller.

11. A device according to claim 10 wherein said rollers are spaced apartaround the entire periphery of said drum.

12. A device according to claim 10 wherein each of

1. A hoisting device comprising: a housing, a drum rotatably mounted insaid housing, said drum being formed with a plurality of axially spacedparallel grooves in planes perpendicular to the axis of said drum, arope formed intermediate its ends to provide a plurality of windingsrespectively received in said grooves and junctures connecting adjacentwindings, means for deflecting said rope from one winding to an adjacentwinding during rotation of said drum with the deflected portions of saidrope forming said junctures in engagement with the periphery of saiddrum, said deflecting means comprising a roller free for axial movementand rotatably supported in said housing and in engagement with a windingof said rope at one side of the latter, said drum being formed at one ofits opposite ends with an annular coaxial abutment and said roller beingformed with an annular abutment adapted to engage said drum at said drumabutment to limit movement of said roller axially relative to said drum.2. A device according to claim 1 wherein said drum is formed with acoaxial abutment at each end and said roller is rotatably supported on ashaft carried by said housing and is adapted to shift axially on saidshaft into engagement with one or the other of the abutments on saiddrum.
 3. A device according to claim 1 wherein said roller is providedwith a peripherally extending groove in registration with an adjacentundeflected winding therein.
 4. A hoisting device comprising: a housing,a drum rotatably mounted in said housing, SAID drum being formed with aplurality of axially spaced parallel grooves in planes perpendicular tothe axis of said drum, a rope formed intermediate its ends to provide aplurality of windings respectively received in said grooves andjunctures connecting adjacent windings, means for deflecting said ropefrom one winding to an adjacent winding during rotation of said drumwith the deflected portions of said rope forming said junctures inengagement with the periphery of said drum, a tension roller free foraxial movement and supported for rotation relative to said housing,means urging said roller radially inwardly of said drum, said rollerbeing provided with a plurality of peripherally extending groovesadapted to receive said rope windings therein for reducing the pressureon said rope, said drum being formed at one of its opposite ends with anannular coaxial abutment and said tension roller being formed with anannular abutment adapted to engage said drum abutment to limit movementof said roller axially relative to said drum.
 5. A device according toclaim 4 wherein said tension roller is supported for axial movement topermit shifting of said roller by said rope windings.
 6. A deviceaccording to claim 4 wherein said drum is formed at each of its oppositeends with an axially inwardly directed coaxial shoulder and said rolleris supported for slidable axial movement into engagement with one or theother of said shoulders.
 7. A hoisting device incorporating automaticreeving wherein a wire rope is reeved around a drum in a plurality ofwindings and means is provided for leading the free end of such ropecircumferentially around said drum to so form said windings withoutmanual intervention, said device comprising: a housing, a drum rotatablymounted on said housing, a rope formed intermediate its ends to providea plurality of parallel windings in planes at right angles to the axisof said drum, means for holding said windings against axial shiftingrelative to said drum, shunt rollers for deflecting said rope from onewinding to an adjacent winding during rotation of said drum with thedeflected portions of said rope in engagement with the periphery of saiddrum, a plurality of tension rollers arranged in a circular row aroundthe entire periphery of said drum, and means for urging said tensionrollers radially inwardly of said drum and against said windings toincrease the traction of the latter relative to said drum, adjacent ofsaid shunt and tension rollers being spaced sufficiently close togetherthat the end of a semi-rigid rope being reeved around the drum andextending tangentially from said drum under one roller is deflectedradially inwardly toward the drum by an adjacent roller to allow suchautomatic reeving.
 8. A device according to claim 7 wherein a shuntroller is interposed between at least one pair of adjacent tensionrollers.
 9. A hoisting device comprising: a housing, a drum rotatablymounted in said housing, said drum being formed with a plurality ofaxially spaced parallel grooves in planes perpendicular to the axis ofsaid drum, a rope forward intermediate its ends to provide a pluralityof windings respectively received in said grooves and juncturesconnected adjacent windings, means for deflecting said rope from onewinding to an adjacent winding during rotation of said drum with thedeflected portions of said rope forming said junctures in engagementwith the periphery of said drum, said rope having a loaded end and aslack end whereby the tension in said rope decreases along the lengthsof said windings toward said slack end, said groove being formed to alarger diameter at said loaded end than at said slack end to reduce therelative movement between rope and drum and to improve traction anddecrease wear, the difference in diameter between the loaded and slackends of the drum being in the order of the difference in lengThs of thewindings at said ends due to elongation of the rope at said loaded end.10. A hoisting device comprising: a housing, a drum rotatably mounted insaid housing, said drum being formed with a plurality of axially spacedparallel grooves in planes perpendicular to the axis of said drum, arope formed intermediate its ends to provide a plurality of windingsrespectively received in said grooves and junctures connecting adjacentwindings, shunt rollers for deflecting said rope from one winding to anadjacent winding during rotation of said drum with the deflectedportions of said rope forming said junctures in engagement with theperiphery of said drum, each of said rollers being rotatably supportedin said housing and each being positioned with its axis of rotationsubstantially parallel to the periphery of said drum and spaced apartperipherally of said drum from an adjacent roller.
 11. A deviceaccording to claim 10 wherein said rollers are spaced apart around theentire periphery of said drum.
 12. A device according to claim 10wherein each of said rollers is provided with only one shunting elementthereon.